高功率微波辐射对大鼠海马的损伤效应

Studies on the injury effects of hippocampus induced by high power microwave radiation in rat

目的 研究高功率微波 (highpowermicrowave ,HPM)辐射对大鼠海马形态与功能的影响。方法 采用HPM辐射 5 0只Wistar二级雄性大鼠 ,于辐射后 6h及 1、3、7d通过Y迷宫检测学习和记忆能力的变化 ,并取海马组织 ,经HE染色、尼氏体染色、原位末端标记和免疫组化等技术 ,研究海马组织形态变化、细胞凋亡以及神经元特异性烯醇化酶 (neuron specificenolase ,NSE)和胶质纤维酸性蛋白 (glialfibrillaryacidicprotein ,GFAP)表达的变化。结果 HPM辐射后 ,大鼠的学习和记忆能力与对照组比均明显降低 ;海马组织水肿、疏松 ,血管扩张 ,神经元变性、坏死 ,尼氏体减少或消失。损伤以CA4区和齿状回较重 ,且存在剂量 -效应关系。病变在 7d内呈进行性加重趋势。凋亡细胞明显增加。神经元NSE表达增强 ,组织间隙和血管腔内也可见到NSE的表达。星形胶质细胞中GFAP表达增强 ,呈粗纤维状 ,与对照组比明显变短、变粗。结论 HPM可影响实验大鼠学习和记忆能力 ;引起海马组织形态结构改变 ,以神经元变性、凋亡和坏死 ,尼氏体减少及间质水肿为主 ;NSE和GFAP参与了其病理过程。

Objective To study the changes of morphology and function in rat hippocampus induced by high power microwave(HPM) radiation. Methods Fifty male Wistar rats were radiated by HPM.Then their learning and memory abilities were tested with Y maze and were sacrificed 6 h,1 d,3 d and 7 d after radiation.The hippocampus was taken out to study the basic pathologic changes,apoptosis and the expressions of neuron-specific enolase(NSE) and glial fibrillary acidic protein(GFAP) by means of HE staining,Nissel body staining,in situ terminal end labeling and immunohistochemistry. Results The learning and memory abilities of rats reduced significantly after HPM radiation.HPM also resulted in rarefaction,edema and hemangiectasia of hippocampus,nervous cells degeneration and necrosis,decrease or disappearance of Nissel bodies.The injuries were more serious in field CA4 and dentate gyrus,which showed dose-effect relationship,and were progressively aggravated within 7 days.The apoptosis cells were significantly increased.NSE was increased in neurons.The NSE positive areas were also seen in the interstitial matrix and blood vessels.GFAP was increased in astrocytes,which became shorter and thicker. Conclusion HPM can damage the abilities of learning and memory and results in morphologic changes in hippocampus.The major pathologic changes are degeneration,apoptosis and necrosis of neurons and edema in interstitium.NSE and GFAP play an important role in the pathologic process.